The present invention relates to an engine, and more particularly, to a distribution system for blow-by gas of an engine.
Engine blow-by gas refers to all the gasses that are not exhausted through the exhaust manifold. Blow-by gas consists of combustion gasses that bypass the piston rings and enter the crankcase during engine operation. If the crankcase is not vented, this blow-by gas causes a build-up of pressure in the crankcase, resulting in damage to engine seals and environmental pollution through oil leaks and the escape of the blow-by gas and atomized lubricants to the atmosphere.
For these reasons, many methods are used to remove blow-by gas. In the most common method, a PCV (positive crankcase ventilation) valve is opened when the pressure in the crankcase reaches a predetermined level. With the opening of the PCV valve, the blow-by gas enters the intake manifold to be supplied to the combustion chamber together with new intake air.
There are two main considerations when installing a blow-by gas distribution system. The first is concerned with distribution, while the second is concerned with layout. Since blow-by gas is a type of impurity, many negative effects result if it is supplied together with new air into the combustion chamber. In particular, combustion is negatively affected, and if a uniform amount of blow-by gas does not enter each cylinder, a difference in the combustive pressures results such that performance deteriorates and NVH (noise, vibration, and harshness) is significantly increased. Accordingly, it is necessary to optimize an installation location or pathway of a PCV valve 120, as well as where the blow-by gas enters an intake manifold 100.
With respect to layout, the blow-by gas distribution system often interferes with other elements. In fact, interaction between the blow-by gas distribution system and other mechanisms may wear away protective coverings, etc. as a result of vibration.
The blow-by gas distribution system of the present invention is preferably capable of equally distributing blow-by gas to each cylinder. In a preferred embodiment of the present invention, the blow-by gas distribution system comprises an intake manifold, and a blow-by gas passageway. The intake manifold is configured to supply intake air to each cylinder of an engine. The blow-by gas passageway is formed within the intake manifold, and the blow-by gas passageway is configured to uniformly distribute blow-by gas to each cylinder, through the intake manifold.
Preferably, the intake manifold comprises a plenum cap shell, a runner shell, and a center shell. The plenum cap shell is fastened to one side of an engine throttle body, and the plenum cap shell is filled with air supplied from the throttle body. The runner shell is mounted between the plenum cap shell and intake holes of each cylinder of the engine, and is configured to supply intake air supplied to the plenum cap shell to each cylinder. The center shell is mounted between the plenum cap shell and the runner shell, and is configured to guide the intake air filled in the plenum cap shell to the runner shell.
It is preferable that the plenum cap shell is pan-shaped with a predetermined depth, and is separated into two spaces by a partitioning wall.
It is further preferable that the two spaces of the plenum cap shell comprise a filling space, and a supply space. Air supplied from outside the intake manifold is filled into the filling space. The supply space is communicated with the center shell to supply air received from the center shell.
Preferably, the communication of the filling space and the supply space is realized by an aperture formed in the partitioning wall, intake air supplied through the aperture being supplied to the runner shell via the center shell.
It is preferable that the runner shell is realized through a shape in which each of the intake runners is curved, one end of the runner shell being connected to a cylinder head, which is adjacent to a cylinder head cover, and its other end being connected to the center shell.
Preferably, the center shell includes holes, which are formed at a location corresponding to the intake runners of the runner shell at an area adjacent to the runner shell.
It is preferable that the holes of the center shell comprise first holes, and second holes. The first holes contact one end of the runner shell and receive the intake air filled in the plenum cap shell. The second holes contact between another end of the runner shell and intake holes of each cylinder of the engine, the second holes act to exhaust the intake air supplied through the runner shell.
It is further preferable that the blow-by gas passageway comprises first blow-by channel and a second blow-by channel. The first blow-by channel is formed in the center shell and connected to each of the intake runners formed in the runner shell. The second blow-by channel is at a location of the plenum cap shell corresponding to the first blow-by channel such that the blow-bay gas passageway is realized through the combination of the first blow-by channel and the second blow-by channel.
Preferably, the blow-by gas passageway is formed such that its one end is closed while its other end is formed into a blow-by intake pipe that connects to a blow-by gas return hose and protrudes from the intake manifold.
It is further preferable that passage holes are formed in the blow-by gas passageway, and the passage holes communicate with the intake runners formed in the runner shell.
It is preferable that the blow-by gas passageway is connected to a blow-by intake pipe that connects to a blow-by gas return hose, and the blow-by intake pipe is integrally formed with the intake manifold.
In another preferred embodiment of the present invention, the blow-by gas distribution system for an engine comprises an intake manifold and a blow-by gas passageway. The intake manifold is configured to supply intake air to each cylinder of said engine, and is provided with a plurality of intake runners defining air paths communicating with said cylinder of said engine. The blow-by gas passageway is formed within said intake manifold, and is configured to supply blow-by gas to each air path of intake runners of said intake manifold through passage holes. Each air path communicates with said blow-by gas passageway through each passage hole.